Combination photographic and magnetic sound film picture projector



July 29, 1952 E. E. MASTERSON 2,605,364

I COMBINATION PHOTOGRAPHIC AND MAGNETIC SOUND FILM PICTURE PROJECTOR Filed Oct. 29, 1949 2 SHEETS-SHEET 1 Z?- am.

By J/M/ Arrmmw July 29, 1952 E. E. MASTER SON 2,605,364

COMBINATION PHOTOGRAPHIC AND MAGNETIC SOUND FILM PICTURE PROJECTOR 2 SHEETSSHEET 2 Filed Oct. 29, 1949 INVENTOR. EARL E. MAST RSIJN BY five/ 27 Patented July 29, 1952 UNITED stares earner oFrrc-E' CGMBINATION PHoToGRAPHrc ANDIMA- NETIC SOUND FILM PICTURE'PROJECTOR can E. Masters on, Palmyra; N. J. ;jassigfid 1tcf Radio Corporationof America, acorporation of Delaware Application October 29, 1949, Scrial' NB. 124,4?6

- 8" Claims.

This invention relates o motion: picture sound apparatus, and to a' combination motion picture projector and-sound'reproducer for motion picture sound film, particularly of the" narrow or anism in one aajusrea'pdsinonsm taken along the line 4-4 ofFig. 3*. A

Fig. is a view offlthe'mecha'lnism'o'f Fig; 4 in another adjustedflpositiong sixteen millimeter type'of composite film hav- 5 Fig. 6 is an 'endflviewof'themcuntingmecha ing a single row' of sprocket holes; V nism for the. changeover unit;and"v N Projectors for motion picture films having Fig. 7 is a detailed view/showing; the azimuth photographic sound records thereon are welladjusting mechanism for the'gnag'neticj head. known, the present invention, however, being di- Referring now toth'e drawingsjini which the rected to such'a motion picture projector which 10 same numems identify like 1e1ements,'a standmay' also reproduce motion picture film having a magnetic record in the area usually occupied by the photographic record. Therefore, the projector will reproduce a film with a" photographic sound track, or, by a simpleflrotar'y adjustment, it will reproduce a film having a magnetic sound track thereon. This is accomplished by the use of anextremely small magnetic pickup' head or transducer, such as disclosed and claimed in Grantham co-pending' application,

Ser; I To. 102-,023, filed June 29; 1949, and th'e'provision of a mounting unit therefor which also supports a light reflector. Thus, the projector is-adaptable for sound reproduction from either type of sound record. The invention ;is disclosed as'a'pplied to a standard commercial type off'niotionpicture projector for photographic sofund records, such as the RCA-400 type, althoughit may also be? adapted to other types of'film' projectors. I V f I Theprincipal object ofthe invention, therefore; isjtofacilitate the projection of motion picturesand the reproduction of sound-from either photographic or magnetic film records.

Another object of the ,inventionis to provide animproved combination motion picture and sound'projector which may have the concomitant sound either as a photographic record'or asamagnetic record on the film.

A further object of the invention isto provide an improved pickup system from either magnetic or photographic film records. j Although the novel features which are'believed "to be characteristic of this invention will be pointed out with particularity in the appended claims, the manner of its organization and the mode of its operation will be better understood by referring to the following description, read in conjunction with the accompanying drawings,.

; nism throjigh the ard motion p cture' unitis; shown at 5,..a section 6 thereof containing the 'projeotionlight source,

amplifier, and a section 'ljcontaining the' other.

necessary equipmntfor, afdvanci n'gland projectaving" a gate sect on I. The," film; is ,pulled rom. 9. r l i r t? n a d; vanced intermittently "by a pm-down mechaojectiomgt' ll, ovef'a'roller find r pre rsft le d' oi drum 15 over ,a' filterroller l 'l',arourid ,.a sprocket I8. and under a guiidef roller 1.91 ...'I he'.film is wound on the usual gtakupreel', :not s own;

Referringnow toFigs. l and z i howih'g the soundreproduction portionof the system, 'a lamp cu ha a l t. s u ce am L lther'iii the ht b n rojec e ro t e fil e and fiected by reflector 2 3 through the objective lens unit 25. As shown in Figs. 2 and 3, the film 8 overhangs the sound drum' I5 and, when a photographic 'record is in the position shown at 21, light, as shownby dOtted;1i.ne2 8,,iS, projected through the sound track toia mirr r SD from which is is reflected through a window 3! to a photoelectric cell within the. housing .32. Thus, asithe film is advanced intermittently through gate ll and'continuously past the light beam 28, the picture is'projected andthesouhdmeproducedin the normal manner, well k nown in the art i-si teen millimeter mbuon'pietii ''fi m' havinga photographictrack' thereon," th sound track .lieson the emulsion errat which faces the light source'22 while, when a'mag'netiotrack is applied to such 'a'film,"it is'on theibase'or opposite side of the film. Thus, to provide acornbination photographic fandfmagnetic track reproducing 'unit for the prdjectohthemagnetic unit must be positiondwithinthe'drum [5 so as to contact the magnet ctrack'. This "is'provided for by the "adjustable unit shown in? detail in Figs. 3 to 6, inclusiveffwherein' either the mirror 30 may be positionedbehind the sound track edge of the film ll, asshownin Figs. 2 and 4, or the magnetic head 35, disclosed and claimed in the above mentioned eo-pending application,

, may be positioned; in contact with a magnetic record- 3 on the, film 4, ',as shown in Fig-. 5.' The drum [5 is under-cut, as shown at 3'6, and is mounted on a shaft 31 in a ball bearing 38 within 4| by overlapping flanges, as shown at 42, so thatv the bracket is rotatable around the longitudinal axis of the ring 4|. Between the ring 4| and 44 to maintain the bracket in fixed longitudinal and rotatable position. The ring is attached to the frame by suitable screws 50, 5|, and 52, an I adjustable, curved stop sector 46 having a slot 41 therein being held by a screw 52 on the ring 4| and providing the proper stopping position for accurately locating the head 35 when the bracket 4i) is rotated slightly less than ninety degrees by means of a shifting l'e'vr'j48. That is, the operating position of the-head 35 is determined by engagement of the pin54with'the upper end of the sector 46, as viewedinFig. 5. To bring the mirror 39 into operating position, thebracket 40 is rotated'clockwiseuntil the pin 54 engages the head of the screw 59. 1 v

The portion of bracket 40 is "cut away, as shown at 56, topermit light from the mirror 39 to be projected to the window 3|. At approximately ninetydegrees from the mirror 30 is a slot 51 having a fiat surface section 58' and a curved surface "section 59" (see Fig.1), in which the magnetic head'35 is positioned. The head is held in the slot'5l by an azimuth determining spring 6 I and a stop 52held, respectively, on the'bracket 49 by" screws 63and164, Thespringfil exerts a constant pressure onthe head to forceit against the stop 62, and thestope62 may be adjusted to rotate the'gap 66 in the head in either direction to make it perpendicular to the motion of the film 4. The broken-'lines 6l-show this adjustment.

Thus, to reproduce the film-8 carrying a-photographic soundtrack, the shifting lever 48 is thrown to the position-shown in Fig. 4, abutting the pin 54 against the screw '50, so that the mirror 39 will reflect the light beam 28 passing through the film to the-photoelectriccell, as shown in Figs. 2 and l. To reproduce the film'4 with a magneticrecord 3, the lever is thrown tothe position shown' in Fig. 5, the stop pin 54 abutting the upper end of the sector 46, the magnetic head 35 then contacting the film. To secure the desired contact between the head andmagnetic track,.the bracket 49 has'an. axis of rotation'at point a whereas the axis of rotation of the shaft 37 and drum I5. is at point D. Thus,when the reproduce head 35 is in the position shown in Fig. 4, it is spaced from the outside surface of the rim of the drum l5, as shown by broken line 69, and when rotated to the position shown in Fig. 5, it is moved radially with respect to the drum, and thus, makes firm contact with the magnetic record material on the film. i

1. A sound reproducing unit for magnetic film records, comprising a, sound drum, means for advancing film over said drum, a bracket mounted on an axis parallel with the axis of said drum and having a, portion extending within said drum, a magnetic reproducing head mounted on said bracket, and means for rotating said bracket to position said head in two positions substantially ninety degrees apart, said head contacting said film in one of said positions.

2. A' sound reproducing unit in accordance with claim 1, in which said axis of rotation of said bracket is spaced from the axis of rotation 4 of said drum, said magnetic head being spaced. from said film in one position and contacting said film in another position.

3. A sound reproducing unit for a motion picture projector, comprising a sound drum, means for advancing a motion picture film over said drum, a shaft for said drum, a rotatable bracket frame 39, is a spacing washer 43, and between. surrounding said shaft, said bracket rotating on the bracket 40 and spacer 43, is aspring washer an axis parallel with and spaced from the axis of said shaft, a magnetic head mounted on said bracket, means for rotating said bracket to position said head in two positions substantially ninety degrees apart, and means for predetermining the stopping positions of said bracket and stopping said bracket at said positions.

4. A rotatable mount positioned partially within a film supporting drum over which a portion of film passing thereover hangs comprising a frame, a ring attached to said frame and havin an internal flange thereon, a substantially cylindrically shaped bracket having an external flange at one end adapted to contact said internal fiange ofsaid ring, resilient means for applyingpressure to said ring and bracket for maintaining the contacting surfaces of said fianges thereof in contact, an element on a portion of one end of said bracket under the overhanging portion of said film, and a second element on said portion spaced approximately ninety degrees from said first element.

5. A rotatable mount in, accordance with claim 4, in which means are provided for adjusting the position of said second mentioned element on said bracket.

6. In a motion picture projector and sound reproducing system in which a film is intermittently advanced at one position and continuously advanced at another position, a sound reproducing structure comprising a rotatable sound drum at said other position over which said film passes, a light source, means for directing light through the sound track portion of said film as it passes over said drum, a shaft for said drum, a photocell adjacent said drum, a bracket having a portion adjacent said film as it passes over said drum, a mirror on the side of said film opposite said light source for reflecting light emerging from said film to said photocell, a magnetic sound reproducing head on said bracket adapted to be moved into contact with said film, and means for rotating said bracket. 9

7. A motion picture projector and sound reproducer in accordance with claim.6, in whichsald bracket rotating means includes overlapping flanges, the axis of rotation of one of said flanges being parallel with and spaced from the axis of said drum shaft.

8. A rotatable mount in accordance with claim 4, in which said 'first ,mentioned element is a mirror and said second mentioned element is a magnetic head.

EARL E. MASTERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

